1. You should pay attention to me.

2. You should draw attention from the audience.
3. You should get attention from the classmates.
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Are they all grammatical? Do we have to use only 'to' in Sentence 1? Do we have to use 'from' in Sentence 2 and 3?
Do you have some more expressions which can be used, similar to 'pay attention to'?

1. "You should pay attention to me." - This sentence is grammatically correct. The phrase "pay attention to" is used to indicate that someone should focus their attention on something or someone.

2. "You should draw attention from the audience." - This sentence is grammatically correct. In this case, the phrase "draw attention from" is used to indicate that someone should attract or gain the interest or notice of the audience.

3. "You should get attention from the classmates." - This sentence is grammatically correct. In this case, the phrase "get attention from" is used to indicate that someone should receive or obtain the focus or notice of the classmates.

Although the preposition "to" is commonly used with the phrase "pay attention," there can be variations depending on the context. In sentence 1, using "to" is appropriate because the attention is being directed towards the speaker.

In sentence 2 and 3, the preposition "from" is used because the attention is being acquired or obtained from someone else (the audience or classmates). It implies a direction from which the attention is coming.

Here are some more expressions that can be used to convey a similar meaning to "pay attention to":

- Focus on
- Concentrate on
- Give consideration to
- Show interest in
- Direct your attention to
- Be attentive to
- Take notice of

These expressions can help to convey the idea that someone should give their attention, consideration, or focus to a particular person, event, or task.

Yes, all three sentences are grammatically correct. However, there are slight variations in the prepositions used in each sentence, and there are alternative expressions you can use for "pay attention to."

In Sentence 1:
"You should pay attention to me." - This is a common phrasing to indicate that someone should focus their attention on you.

In Sentence 2:
"You should draw attention from the audience." - This means that you should do something to capture the audience's attention.

In Sentence 3:
"You should get attention from the classmates." - This suggests that you should find a way to receive attention from your classmates.

Regarding your additional questions:

1. Sentence 1: While "pay attention to" is the most common expression, you can also use "give attention to" in a similar way to indicate that someone should give their attention to you.

2. Sentence 2 and 3: While "from" is used in these sentences, you can also use "get attention of" or "capture the attention of" instead of "draw attention from." For example: "You should get the attention of the audience" or "You should capture the attention of your classmates."

Remember, slight variations in prepositions or expressions can convey similar meanings, but make sure the chosen expression fits the context appropriately.